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Monitoring strata behavior due to multi-slicing top coal caving longwall mining in steeply dipping extra thick coal seam

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International Journal of Mining Science and Technology 2017年第1期27卷 179-184页

作者： Yun Dongfeng Liu Zhu Cheng Wendong fan Zhendong Wang Dongfang Zhang Yuanhao CoUege of Energy Xi'an University of Science and TechnologyXi'an 710054China Ministry of Education Key Laboratory of Western Mine Exploitation and Hazard Prevention Xi'an University of Science and TechnologyXi'an 710054China College of Architecture and Civil Engineering Xi'an University of Science and TechnologyXi'an 710054China Huating Coal Group Co. Ltd.Huating 744100China Dongxia Coal Mine Huating Coal Group Co.Ltd.Huating 744100China

For studying the strata behavior due to multi-slicing top coal caving longwall mining along-the-strike direction in steeply dipping extra thick coal seams,the shield support pressures of the upper and lower slices of panel 37220 in Dongxia Coal Mine were monitored using the KJ513 dynamic monitoring *** set up rooms adopted the "horizontal line-arc segment-inclined line" form and used different types of shield *** results show that the strata pressure of upper slice panel 37220-1 changed slightly along the strike direction,while along the dip direction it exhibited strong to weak pressure from bottom to *** first weighting interval of lower slice panel 37220-2 was about 60.8 m,and the average periodic weighting interval were about 22.6 *** strata behavior of panel 37220-2 exhibited a spatiotemporal characteristic in that periodic weighting occurred first in the middle-upper part,followed by the middle and upper parts,arc segment,and finally the lower *** the periodic weighting,the weighting interval and intensity also exhibited strong space *** average dynamic load coefficient was 1.48 and the maximum lateral load of the side shield was 20-25 MPa.

关键词： Monitoring Steeply dipping seam Slicing Longwall along the strike Fully mechanized top-caving face Strata behavior

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Fully-integrated ultra-wide band LNA in 0.18μm CMOS technology for 3-10 GHz applications

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High Technology Letters 2019年第4期25卷 364-368页

作者： Du Jianchang fan Chen Wang Zhigong Xu Jian Institute of RF-&OE-ICs Southeast University

The paper presents a fully integrated ultra-wide band(UWB)low noise amplifier(LNA)for 3-10 GHz *** employs self-biased resistive-feedback and current-reused technique to achieve wide input matching and low power *** improved biased architecture is adopted in the second stage to attain a better gain-compensation *** design is verified with TSMC standard 1 P6 M 0.18μm RF CMOS *** measurement results show that the parasitic problem of the transistors at high frequencies is solved.A high and flat S21 of 9.7±1.5 dB and the lowest NF 3.5 dB are achieved in the desired frequency *** power consumption is only 7.5 mA under 1.6 V *** proposed LNA achieves broadband flat gain,low noise,and high linearity performance simultaneously,allowing it to be used in 3-10 GHz UWB applications.

关键词： ultra wide band(UWB) self-biased current-reused gain compensation CMOS low noise amplifer(LNA)

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Preparation of porous hollow silica spheres via a layer-by- layer process and the chromatographic performance

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Frontiers of Materials Science 2017年第1期11卷 33-41页

作者： Xiaobing WEI Cairong GONG Xujuan CHEN Guoliang fan Xinhua XU School of Materials Science and Engineering Tianjin University Tianjin 300350 China Analysis and Testing Center Shandong University of Technology Zibo 255000 China

Hollow silica spheres possessing excellent mechanical properties were successfully prepared through a layer-by-layer process using uniform polystyrene （PS） latex fabricated by dispersion polymerization as template. The formation of hollow SiO2 micro-spheres, structures and properties were observed in detail by zeta potential, SEM, TEM, FTIR, TGA and nitrogen sorption porosimetry. The results indicated that the hollow spheres were uniform with particle diameter of 1.6 μm and shell thickness of 150 nm. The surface area was 511 m2/g and the pore diameter was 8.36 nm. A new stationary phase for HPLC was obtained by using C18-derivatized hollow SiO2 micro-spheres as packing materials and the chromatographic properties were evaluated for the separation of some regular small molecules. The packed column showed low column pressure, high values of efficiency （up to about 43 000 plates/m） and appropriate asymmetry factors.

关键词： PS latex layer-by-layer hollow silica spheres packing materials

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Velocity model and time-depth conversion for the northwestern South China Sea deepwater areas

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Acta Oceanologica Sinica 2015年第4期34卷 56-61页

作者： LIU Aiqun CHEN Dianyuan LI Wentuo fan Caiwei HE Jianwei Zhanjiang Branch of China National Offshore Oil Corporation Limited

There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.

关键词： time-depth conversion velocity modeling deepwater areas continental slope South China Sea

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Efficient Synthesis of Functionalized Benzimidazoles and Perimidines： Ytterbium Chloride Catalyzed CmC Bond Cleavage

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Chinese Journal of Chemistry 2011年第9期29卷 1880-1886页

作者： Cai, Lijian Ji, Xiaofeng Yao, Zhigang Xu, fan Shen, Qi Key Laboratory of Organic Synthesis College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China

An efficient method is developed for the synthesis of functionalized benzimidazoles and perimidines by the condensation of aryl diamines with β-carbonyl compounds catalyzed by ytterbium chloride. The reactions give g... 详细信息

关键词： lanthanide C--C activation catalysis ytterbium chloride benzimidazole perimidine

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Study of relationship between wave transport and sea surface temperature anomaly(SSTA) in the tropical Pacific

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Acta Oceanologica Sinica 2016年第9期35卷 58-66页

作者： SHI Yongfang WU Kejian ZHU Xianye YANG fan ZHANG Yuming Key Laboratory of Marine Science and Numerical The First Institute of OceanographyState Oceanic Administration College of Oceanic and Atmospheric Sciences Ocean University of China National Marine Environmental Monitoring Center State Oceanic Administration

Large-scale water transport is one of the key factors that affect sea surface temperature anomaly（SSTA） in the eastern equatorial Pacific（EEP）.The relationship between the wave transport in the tropical Pacific and the SSTA in the EEP is examined by different methods,including band-pass filtering,period analysis,correlation analysis,significant analysis,and empirical orthogonal function（EOF） *** have found that the eastward shift of the wave transport anomaly in the tropical Pacific,with a period of 2 a and enhancing the transport of warm waters from the western Pacific warm pool,precedes the increase of sea surface temperature（SST） in the *** wave transport and the SSTA in the EEP have a maximum correlation of 0.65 with a time-lag of 6 months（transport variation precedes the temperature）.The major periods（3.7 a and 2.45 a） of the wave transport variability,as revealed by the EOF analysis,appear to be consistent with the SSTA oscillation cycle in the *** on the first occurrence of a significant SSTA in the Ni？o 3 region（5°S–5°N,90°–150°W）,two types of warm events are *** wave transport anomalies in two types present predominantly the west anomaly in the tropical Pacific,it is that the wave transport continues transport warm water from west to east before the onset of the warm *** impact of wave-induced water transport on the SSTA in the EEP is confirmed by the heat flux of the wave *** wave transport exerts significant effect on the SSTA variability in the EEP and thus is not neglectable in the further studies.

关键词： wave transport eastern equatorial Pacific sea surface temperature anomaly warm events

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Density functional theory (DFT)-based modified embedded atom method potentials: Bridging the gap between nanoscale theoretical simulations and DFT calculations

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Science China Chemistry 2010年第2期53卷 411-418,454-455页

作者： YANG fan LIU YuWen OU LiHui WANG Xin CHEN ShengLi Hubei Electrochemical Power Sources Key Laboratory Department of ChemistryWuhan UniversityWuhan 430072China School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingapore

A density functional theory (DFT)-calculation scheme for constructing the modified embedded atom method (MEAM) potentials for face-centered cubic (fcc) metals is presented. The input quantities are carefully selected and a more reliable DFT approach for surface energy determination is introduced in the parameterization scheme, enabling MEAM to precisely predict the surface and nanoscale properties of metallic materials. Molecular dynamics simulations on Pt and Au crystals show that the parameterization employed leads to significantly improved accuracy of MEAM in calculating the surface and nanoscale properties, with the results agreeing well with both DFT calculations and experimental observations. The present study implies that rational DFT parameterization of MEAM may lead to a theoretical tool to bridge the gap between nanoscale theoretical simulations and DFT calculations.

关键词： theoretical simulations MEAM DFT parameterization nanoparticles

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Research on Performance Optimization of Spark Distributed Computing Platform

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Computers, Materials & Continua 2024年第5期79卷 2833-2850页

作者： Qinlu He fan Zhang Genqing Bian Weiqi Zhang Zhen Li School of Information and Control Engineering Xi’an University of Architecture and TechnologyXi’an710054China Shaanxi Institute of Metrology Science Xi’an710043China

Spark,a distributed computing platform,has rapidly developed in the field of big *** in-memory computing feature reduces disk read overhead and shortens data processing time,making it have broad application prospects in large-scale computing applications such as machine learning and image ***,the performance of the Spark platform still needs to be *** a large number of tasks are processed simultaneously,Spark’s cache replacementmechanismcannot identify high-value data partitions,resulting inmemory resources not being fully utilized and affecting the performance of the Spark *** address the problem that Spark’s default cache replacement algorithm cannot accurately evaluate high-value data partitions,firstly the weight influence factors of data partitions are modeled and ***,based on this weighted model,a cache replacement algorithm based on dynamic weighted data value is proposed,which takes into account hit rate and data *** integration and usage strategies are implemented based on LRU(LeastRecentlyUsed).Theweight update algorithm updates the weight value when the data partition information changes,accurately measuring the importance of the partition in the current job;the cache removal algorithm clears partitions without useful values in the cache to releasememory resources;the weight replacement algorithm combines partition weights and partition information to replace RDD partitions when memory remaining space is ***,by setting up a Spark cluster environment,the algorithm proposed in this paper is experimentally *** have shown that this algorithmcan effectively improve cache hit rate,enhance the performance of the platform,and reduce job execution time by 7.61%compared to existing improved algorithms.

关键词： Spark memory optimization memory replacement strategy

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Analysis on the Parameter Selection Method for FLUSH+RELOAD Based Cache Timing Attack on RSA

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China Communications 2015年第6期12卷 33-45页

作者： ZHOU Ping WANG Tao LI Guang ZHANG fan Zhao Xinjie Department of Information Engineering Ordnance Engineering College The Institute of North Electronic Equipment Department of Information Science & Electrical Engineering Zhejiang University

FLUSH+RELOAD attack is recently proposed as a new type of Cache timing *** are three essential factors in this attack,which are monitored *** and waiting ***,existing literature seldom exploit how and why they could affect the *** paper aims to study the impacts of these three parameters,and the method of how to choose optimal *** complete rules for choosing the monitored instructions based on necessary and sufficient condition are *** to select the optimal threshold based on Bayesian binary signal detection principal is also ***,the time sequence model of monitoring is constructed and the calculation of the optimal waiting interval is *** experiments are conducted on RSA implemented with binary square-and-multiply *** results show that the average success rate of full RSA key recovery is89.67%.

关键词： side channel attack Cache timingattack RSA square-multiply algorithm expo-nentiation

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Demonstration of full-parallax three-dimensional holographic display on commercial 4 K flat-panel displayer

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Chinese Optics Letters 2016年第1期14卷 26-30页

作者： Frank C. fan Sam Choi C. C. Jiang AFC Technology Co. Ltd. Shenzhen 518104 China

A novel method for a full-parallax three-dimensional （3D） holographic display by means of a lens array and a holographic functional screen is proposed. The process of acquisition, coding, restoration, and display is described in detail. It provides an efficient way to transfer the two-dimensional redundant information for human vision to the identifiable 3D display for human eyes. A holo-video system based on a commercial 4 K fiat-panel displayer is demonstrated as the result.

关键词： Geometrical optics Holography

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